Accessory process of lumbar vertebra ...

Description

This is a small projection from the posterior base of the transverse (costal) process. This, in combination with the mammillary process, forms the true transverse process that is homologous with the transverse processes of the thoracic region. It is a muscle attachment site, like all true transverse processes, for epaxial muscles.

Etymology

The word accessory arises from the Latin accessus, a compound word composed of ad meaning to or plus and cedere the verb meaning to go. Therefore, something that goes to, supplements, or aids. Process is a term used in anatomy to describe a projection on a bone. It comes from the Latin pro- meaning forward and cessus for gone. It is an old term that can be traced back to the writings of the early anatomist Celsus.